Project description:Objectives: Our work focuses on the responses of Solanaceous plants to viruses that cause economically important diseases in tree fruits. Using mock inoculated leaf tissue as a reference, we plan to compare the gene expression profiles of Nicotiana Benthamiana plants infected with one of three viruses; Plum Pox Potyvirus (PPV), Tomato Ringspot Nepovirus (ToRSV), and Prunus Nectrotic Ringspot Nepovirus (PNRSV). Our goals are as follows: (1) Identify genes that are induced/repressed in response to individual viruses. (2) Identify genes that are induced/repressed in response to all 3 viruses. (3) Compare results to existing potato array data to look for similarities in responses to other pathogens. Experimental Design: Nicotiana benthamiana plants were inoculated with one of three viruses: PPV, ToRSV, or PNRSV. 3 week old plants were inoculated by rubbing virus infected plant sap onto leaves dusted with carborundum. Control plants were mock inoculated using sap from healthy plants. All plants were maintained in a growth chamber at 22C for 18 days. 8 plants were inoculated with each virus or mock inoculated. This experiment was repeated twice. 4 biological replicates derived from 2 virus infected plants from each replica experiment (4 plants) are to be used for hybridizations. RNA from all mock inoculated plants was similarly pooled to create 4 biological replicates. Each replicate control will serve as a universal reference sample that is to be hybridized pair wise with each of the three virus infected samples. RNA extraction: After 18 days, un-inoculated leaves displaying clear symptoms were harvested and immediately frozen in liquid N2. Total RNA was purified using Trizol according to TIGRs listed protocol. RNA was subsequently treated with Turbo DNA-free RNase (Ambion cat#1907). Finally, total RNA was further purified on RNeasy columns (Qiagen) according to manufacturer’s instructions and quantified using a Nanodrop spectrophotometer. Keywords: Reference design
Project description:Duckweeds are a monophyletic group of rapidly reproducing aquatic monocots in the Lemnaceae family. Spirodela polyrhiza, the Greater Duckweed, has the largest body plan yet the smallest genome size in the family (1C = 150 Mb). Given their clonal, exponentially fast reproduction, a key question is whether genome structure is conserved across the species in the absence of meiotic recombination. We generated a highly contiguous, chromosome-scale assembly of Spirodela polyrhiza line Sp7498 using Oxford Nanopore plus Hi-C scaffolding (Sp7498_HiC) that is highly syntenic with a related line (Sp9509). Both the Sp7498_HiC and Sp9509 genome assemblies reveal large chromosomal misorientations in a recent PacBio assembly of Sp7498, highlighting the necessity of orthogonal long-range scaffolding techniques like Hi-C and BioNano optical mapping. Proteome analysis of Sp7498 verified the expression of nearly 2,250 proteins and revealed a high level of proteins involved in photosynthesis and carbohydrate metabolism among other functions. In addition, a strong increase in chloroplast proteins was observed that correlated to chloroplast density. This Sp7498_HiC genome was generated cheaply and quickly with a single Oxford Nanopore MinION flow cell and one Hi-C library in a classroom setting. Combining these data with a mass spectrometry-generated proteome, demonstrates that duckweed is a model for genomics- and proteomics-based education.
Project description:The affinity of the echinoderm pentaradial body plan with that of the ancestral bilateral symmetry remains one of the biggest zoological puzzle. Here, we revisited this classical zoological problem using RNA tomography and HCR in situ hybridization in the sea star Patiria miniata.